aldridge and h



A. ALDRIDGE AND H. TERHUNE. `ELECTROMAGNEICALLY CONTROLLED BOARD DROPHAMMER.

APPLICATION FILED OCT. 30. IDH.

A. ALDRIDGE'AND H. TERHUNE. ELECTROMAGNETICALLY CONTROLLED BOARD DROPHAMMER.

APPLICATION FILED OCT-30, |917. 1 ,3 1 1 ,942. Patented Aug. 5, 1919.

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UNITED STATES PATENT oEEIcE.

ARTHUR ALDRIDGR AND HOWARD TERHUNE, or CHAMBERSBURG, PENNSYLVANIA,AssIeNoRs To CHAMBRRSBURG ENGINEERING COMPANY, or CHAMBERSBURG,PENNSYLVANIA, A CORPORATION or PENNSYLVANIA.

y I To all whom t may concern:

Be it known that we, ARTHUR ALDRIDGE and HOWARD TERHUNE, citizens of theUnited of the parts required to secure roll move .ment and maintain therolls in engagement with the board.I

A further purpose is to rovide gravity releasefor the rolls instead ogravity setting thereof, reducing the weight of parts required andthrowing the rolls to released position in case of failure of theroll-setting mechanism.

A ,further purpose is to. provide interchangeably for brush actuatedcontact or positive switch throlw to make and break the contacts toenergize and denergize the electromagnetic clutch operating mechanism.

4A further purpose is to use a solenoidal I electromagnetic resilientpull for the initial movement and major part of vthe clutch setl LE)tingthrow of the board engaging rolls and to supplement the solenoidal pullof an electromagnet at the end of the stroke'in order to make theengagement of the rolls with the board more positive. In this connectionwe cause compression of a releasing spring during the setting movementof the solenoid and use this spring to assist in quick release of therolls from the board when the current is Withdrawn. j A

' A further purpose is to combine solenoidal and electromagnetic `pulland retention of the rolls in their setting engagement with the' boardand to combine spring and gravity operation for the release when thelelectric current is cut off. y

Further purposes will appear in the speciication and in the claimsthereof.

Our invention contemplates the methods involved as well as the apparatusin connection with which the methods are explained.

Ve have preferred to illustrate our in- Specication of Letters Patent.

Application led October 30, 1917.

ELECTROMAGN'ETICALLY-CONTBOLLED BOARD DROP-HAMMER.

Patented Aug. 5, 1919.

serial No. 199,259.

vention by but one form, selecting for the purpose a form which in usehas proved to be practical, elicient and inexpensive, and which at thesame time well illustrates the principles of our invention. l

Figure 1 is a front elevation omitting some of the well known parts ofthe preferred form of cpr invention.

Fig. 2 '1s a side elevation, partly broken away, of the structure seenin Fig. 1, but with the omitted parts shown.

Fig. 3 is'an enlarged section of a port-ion -of the structure, seen inFig. 1.

Figs. 4 and 6 are sections taken upon the lines L1--4`and 6-6 in Fig. 1.

. Fig. 5 is a perspective view of one of the `parts seen 1n Flg. 3.

'all old and the latter release an old form of board clamps through themedium of a rod 11. The rear one of the board clamps and the rear rollof the board rolls are capable of adjustment as in previous hammers bymeans of adjusting bars 12, 13 respectively held and shifted by theusual devices. At their uppell ends these bars connect with adjustinglevers 11 and 15 to turn eccentric shaft-carrying sleeves withinbearings as before. The shifting of the front clamp of the board clampsby the treadle and the driving of the board rolls have not beenchanged.,

In existing drop hammers with which we are familiar the shaft of one ofthe board rolls, preferably the front roll, is carried by an eccentricsleeve or mount which is oscillated within a fixed outer bearing by aheavy front rod or friction bar to move that roll toward and away fromits mate so that both will grip the board 1G to lift or release it andthe ram 17. In these hammers the weight of the front rod-v andconnections are relied .upon to `keep the rolls in operative engagementwith the board, and the ram or a part connected therewith must 'liftthis heavy rod and the connections by parts, resulting in breakage andfailure of operation. Our invention is intended to replace the weightcontrol by electromagnetic control, to use electric connections, with orwithout mechanical switch actuation, instead of the purely`mechanicaltappet actuation of the rod, preferably lifting the roll-sleeve arm forroll engagement instead of lowering it (or over counterbalancing the armif it be lowered, so that there shall be gravity or spring return toreleased position) and to supply quick release when the current isinterrupted.

The roll-carrying eccentric sleeves 18 for. the front roll arepreferably oscillated within its bearing 19 afshort distance onlytothrow the center of the roll 'shaft to opposite sides of a perpendicularline through the eccentric center.

Among the many forms in which the electric current could be utilized tothrow eccentric arm 20 we have preferred to use 'the form in which theelectro-magnetic device,.`exemplied in combined electromagnet andsolenoid 21, lies above the arm, in order that the weight of the partsmay cause release of the rolls in case of' failure of the electriccurrents The electromagnetic device 21, best seen in Fig. 3, is of theiron-clad type including -an outer shell 22 intended to act as part ofthe magnetic circuit and lmade of ironl for this purpose. It carries aninwardly directed magnet pole 23 and' provides a space. outside the poleand inside the shell for a winding 24, hollow at 25 below the and at`the same time forma solenoidal eX- tension.

y The solenoid and magnet pole both act `upon the same armature`26 ofmagnetic material.

For'- convenience, and t'o permit the use lof a poorer quality ofmaterial for the rod 27, the latter is made separate from the armature.It is guidedin bracket 28 and is'conpole, intended to energize themagnet pole nected at its lower end with an arm 29.

pivoted at 30. t

We have shown the magnet shell as circularly ribbed at 31 to improve itsqualities -as a distributer of heat, and have indicated a non-magneticstrip at 32 to reduce undesirable leakage of magnetic line.

Thlepin 33 connects betweenr rod 27 and the arm 29. As the rod is guidedto move in a straight line and the arm swings about an arc we havearranged for a sliding connection between the parts, while permittlng.

a well balanced thrust and firm engagement.

Each 0f the sides 34, 35 of the'arm is slotted, as at 36, 37 to recei/veflattened ends of the pin 33 and to give a irmbearing to the flat sidesof the 'pin in each direction of movement while permitting free slidingL .i movement` lengthwise of the sides.

The cen- 'tral part of the pin is left cylindrical to fit within thesocket 38 upon the end of the rod. ThleJ pin is Jinserted through eitherof the cylindrical passages 39, 40 which communicate with the slots andmake them, in effect, keyhole slots.

The sides of the arm 29 are stiffened by a connecting rib 41 and areextended t0 give support at 42 and 43 to a pin 44 by which arm 29 isconnected to link 45. At its lower end the link is connected by a pin 4Gwith eccentric arm 47.

. It will be seen that the armature and connected parts will be liftedfrom the position shown in F ig. 3, in which the rolls are released fromthe board, to the roll-engaging position by'electromagnetic action whichis almost-wholly solenoidal at the start and largely by a magnet at theupper end of the stroke, making rit possible to secure full contactbetweenthe face 48 ofthe magnet pole and the end 49, of the armaturewhen in full clutching position, if actual contact .be desired.

Even if contact be avoided because ofthe danger of sticking, thisaffords a pull' of increasing strength as the upper position' isapproached, with a maximum hold when the armature is at its uppermostposition and the rolls should most tightly engage the board 16. v

It will also be seen that the weight of the armature and connected partswill combine to drop the arin 29 and to release the rolls fromengagement with the board when the electric current is interrupted,whether by normal operation of the hammer or by accidental orunauthorized interruption of the circuit.

. Because of Vthe desirability of a quicker release than would beprovided by gravity alone, we interpose a spiral 'spring 50 between anys'uitable shoulder or projection 51 upon the rod, and a relatively fixedmember such as the lower part 52 ofi the bracket j 28. This, of course,necessitates design' of an electromagnetic circuit with sufficientlstrength to compress the spiral spring in addition tolifting lthearmature and connected parts. w t

Physical contact between the armature A and the pole facewdesirable onaccount of the greater intensity of th'e magnet hold se. cured thereby,would increase the desirability of using a quick-release.

It will be obvious not onlyv that the form I of electromagnetic pull andconnections for operating each lroll thrownmay be Varied greatly b-utalso that the Variety of means for making and breaking the electriccurrent required is great, varying from` the irrost simple formi ofcopera'ting switch \members, one part being carried by the ram,

to complicated forms of switches, mechanically operated bymeansconnected with the ram.

The invention is preferably illustrated by a mechanicallyoperatedswltch, for which cam operation and an oscillatory shaft have beenselected in preference to other forms that will suggest themselves toany designer in the art, because by this construction bodily movementneed not be given the shaft by the ram, thus reducingthe amount of workto be performed in the movement of the switch operating mechanism.

Describing now the preferred form of contact making device, the electricconnections are protected by the usual tubing 53. At any suitable pointwithin the path of the electric current from the protective inlet switch54, to the electromagnetic device 21, a second 'switch 55 is provided,operated by a gear 56 upon the upper endof its shaft 57 by means of asegment 58. The latter is mounted upon an oscillatory shaft 59 at anyconvenient point along the length of the shaft.

We preferto operate a separate switch by the segment, as indicated, ascompared with the more simple use of the part corresponding to thesegment as itself constituting the movable member of Athe switch.

The shaft is mounted in any type of bearings 60, 61 and one of thebearings is provided with a drag or friction device to prevent the shaftfrom movement by jarring and to prevent it from rebounding angularly atthe ends of its stroke. The particular form of drag which We have shownuses a split in the bearing at 62 with clamps for dra-wing the Ipartstogether to any required extent about the shaft as a means of applyingthe friction.

The shaft 59 is of sufficient length to per` mit engagement by the ramor a part such as bar 63, extending therefrom, with cams adjustablymounted upon the shaft as illustrated by means of clamps 64 and 65. Wehave preferred to form the cams themselves as fins 66 and 67, which areoppositely turned so as to be thrown in opposite angular directions bythe bar 63.

The adjustability of these cams offers the same flexibility ofadjustment of the automatic stroke of the ram to provide for differentdesired heights o'f ram travel and different thicknesses of die, as isprovided with the existing mechanical form of reversal.`

It is quite necessary to provirel a stop for limiting angular movementof t e shaft 59, and also to have hand control of the current reversalsto permit a short stroke ram operation, needed particularly for drawingtong holds, breaking down, cutting ofl' stock, etc. We provide for thisconveniently by a lever arm or handle 68, secured to and controllingHand or treadle lever-sal' is thrown when the hammer is to be started Aand, the Iboard clamps being released by the treadle, the Iram islifted, either by reason of the normal position of the switch 55,because of the position at which the ram had been left, or by movementof the handle 68.

The cams cause the switch 55 to be opened at the upper end of the strokeand closed at the lower end of the strokerespect-ively, when they areengaged by bar 63, and the height of these cams may be varied readily toalter the point of reversal.

fWith the ram at the lower end of its stroke, the electromagnetic deviceis 'energized, resulting in an immediate solenoidal pull upon thearmature which lifts the armature, at the same time compressing thespiral spring and lifting the connections between the armature rod andthe arm 29. As the armature approaches the magnet pole -the latterbegins to pull appreciably also. Theelectromagnetic pull then increasesrapidly, becoming a maximum, coincidentally with contact, or the closestapproach permitted, between the pole and armature faces, correspondingwith complete engagement of the rolls with the board.

The engagement of the rolls with the board causes the ram to be lifteduntil the bar 63 engages the upper cam or until the shaft 59 is turnedby hand to operate`the switch. In either event, the current is thenbroken and the combined expansion of the spiral spring and weight of theparts. cause the front roll to be swung outwardly, releasing4 the boardand allowing it -to drop. These reversing-operations will continueautomatically as long as the treadle is cle-- pressed. Y

We have preferred to make the electromagnetlc device single actlng,using gravity or spring action, or both for movement 1n` the oppositedirection, for the reason that operation in the reverse direction whollyor partly by solenoid or magnet, though entirely practicable, involvesan unnecessary use of electric energy.

It will be evident that we can use solenoidal operation entirely, bysufficiently strengthening the solenoidal pull, or electromagnet pullalone, by shortening the stroke, and our claims are intended to covereither or both of these, broadly,l except where they specifically callfor a different interpretation.

' combined What we claim as new and desire to secure by Letters Patentis 1. A board drop hammer,comprising a frame, board-lifting mechanism,clamp mechanism and a release for the clamp in combination with anelectromagnetic device and connections for drawing the lifting rollstogether for engagement with the board and" contact devices operated bymovement of the ram for making and breaking the electric circuit.

2. In a board drop hammer having a frame, an anvil, a ram, board andelevating rolls, electromagnetic means and connections `for moving oneroll to bring the rolls into engagement with the board.

y 3.A In a board drop hammer having a frame, an anvil, a ram board andelevating folle, electromagnetic means for moving one releasmg bygravity when the circuit is in*A terrupted'.

5. A board drop hammer having a frame, an anvil, aram, board andelevating rolls, inL ombination with connections for bringin; the rollsinto engagement with'the board and a combined solenoidal andelectromagnet lifting means for operating these connections, l v

6. A board drop hammer having a (frame, an anvil, a ram, a board andelevating rolls, in combination with connections for throwing the rollsinto en agement with the board,

solenoi al and means for lifting the connections when the current isthrown on, and connections operated by the ram for making and breakingthe electric circuit. l

7. A power hammer, comprising a frame, an anvil, a ram, a board andlifting rolls, with operating mechanism therefor in combination withcontact making devices operated with -movement of the ram, a solenoidenergized when the contact is made, an armature operating in saidsolenoid, an arm and cam operating mechanism moving one roll toward theother with movementof the arm and connections between the arm andthearmature whereby the rolls are engaged /with the board when thesolenoid is energized. y

`8. A power hammer, comprising a frame, lan anvil, a ram, a board andllftmg rolls, with operating mechanism therefor 1n com bination withcontactv making mechamsm `operated with movement of the ram and. a

electromagnet solenoid energized when the contact is made, an armaturefor the solenoid, connections from the armature, moving one roll towardlthe other with movement of the armature into the solenoid anda magnetpole energized at the same time 'as energization of the solenoid andeffective to draw the armature at the inner'end of the latters stroke.

9. A power hammer, comprising a frame, 'an anvil, a ram, a -board andlifting rolls, with operating mechanism therefor, incombination withcircuit closing mechanism operating with movement of the ram, 'a'

.solenoid energized by the closing of the circuit, an armature movableinto the solenoid and connections between the armature and one of therolls moving the roll toward its mate with initial movement of thearmature and weighted normally 'to withdraw the armature when thecircuit is opened.

10. A power hammer, comprising a frame,

an anvil,'a ram, a board and .lifting rolls, with operating mechamsmtherefor, in coml bination with circuit closing mechamsm opi l eratingwith movement of the ram, a solef noid energized by the closing of theclrcuit, an armature -movable inwardly` and out- Iwardly with respect tothe solenoid, connections between th'e solenoid armature and fone of therolls to move it toward the board with inward movement of the armatureand normally weighted t0 tend to withdraw thev armature'from thesolenoid and a 'spring set by inward movement of the `armature and'tending to assist in withdrawal thereof.

l1. A power hammer, comprising a frame, an anvil, a ram, a board andlifting rolls,

with operating mechanism therefor, in comf armature from the solenoid, aspring set by inward movement of the armature and tend-l Jingto,assistin withdrawal therefrom, and an electromagnet pole reinforcingthe pull of the solenoid upon the armature at the' vextreme inwardposition of the armature;

12. A power hammer, comprisinga frame, an anvil, a. ram, a boardandlifting rolls, with operating mechanism therefor, in combinationwithcircuit closing mechanism yoperatinglwith movement of .the ram, asolenoid energized by the closing o f the circuit,

' an armature movable inwardly and out` `wardly with respect to thesolenoid, vconnections between the solenoid armaturefandy one oftherolls to move it toward -the'boardwith inward movement of the'armature and,

normally weighted to tend to withdraw the armature from the solenoid, aspring set by mward movement of the armature and tending to assist inwithdrawal therefrom, and

an electromagnet pole energized at the same time as the energization ofthe solenoid and cooperating with it to retain the armature in itsinward position.

13. A power hammer,- comprising a frame,

an anvil, a ram, a board and lifting rolls,

with operating mechanism therefor, in combination with a cam sleevesurrounding one of the roll shafts, a bearing for the cam sleeve, an armconnected with the cam sleeve to shift it, thereby moving the rolltoward or away from the board, connections for said arm normallyweighted to hold the roll away from the board and electromagnetic meansenergized through` movement of the ram near the lower extremity of itsstroke to lift the connections and denergized through the movement ofthe ram at the upper end of the stroke.

14. A power hammer, comprising a frame, an anvil, a ram, a board andlifting rolls, having shafts with operating mechanism therefor, incombination with a cam sleeve for the cam sleeve, an arm connected withthe cam sleeve to shift it, thereby moving the roll toward the board, anarmature adapted to 'move'the connections, a solenoid con ected with thearmature, a spiral coil compressed by upward movement of the armature,an electromagnet pole assistingv the solenoid, and common means forener` gizing the solendid and ,pole by reason of downward movement ofthe ram, to lift the connections and set the roll and to denergize thesolenoid and pole with upward .movement of the ram to release theconnec- -tions and roll. l 15. A power hammer, comprising a frame, ananvil, a ram, a board and lifting rolls, with operating mechanismtherefor, in combination with gravity-operated means for normallyreleasing the rolls and electromagnetic means `for lifting thegravityreleased rolls, automatically energized with downward movement ofthe ram and denergized with upward movement of the ram. 16. A powerhammer, comprising a frame, an anvil,.a ram, a board, and lifting rolls,with operating'mechanism therefor, in combination with gravity-operatedmeans for normally holding the rolls apart, and l1fting mechanismtherefor, operated by reason of downward movement of the ran and causinthe rolls to engage the board. 17. power hammer, comprising a frame, ananvil, a ram, a board and liftin rolls, with operating mechanismtherefor, 1n combination with gravity-operated means for jnormallyholding the rolls apart, lifting an'ism for said liftingrolls,electro-magnetically operated means for setting the rolls, and circuitclosing mechanism for said means, closed by reason of downward move#Lment of the ram and opened by reason of np-y ward movement thereof.

19. In a board drop hammer, a frame, an anvil, a ram and a board movablewithin the frame, operating rolls' for lifting the ram, electromagneticmeans for tightening the rolls against the board, an oscillatory shaftcams thereon operated by the movement of the ram, and switch mechanismopened and closed by oscillatory movement of said rod at the upper andlower limits of ram movement respectively, to open and close the circuitthrough the electromagnetic means.

20. In a board drop hammer, lifting rolls for the board, means forshifting one of the rolls, an armature and armature rod, connections formoving the shifting means and pivotally connected with the rod, asolenoidal winding about the armature, an electromagnet energized at thesame time as the solenoid, a magnet shell connected with the magnet poleand in part inclosing the solenoidal windings, and means for ener 'zingthe solenoid and magnet core with own- Ward movement of the board andram.

21. An electromagnetic mechanism forl shifting the roll in a board drophammerl comprising a solenoid and armature therefor rfor givingtheinitial movement to the roll and an electromagnetrpole assistin inthe final movement of the, roll and ho ding 1t firmly in set position.

22. Operating mechanism for shifting the tions with energization thereofand retaining them in raised position.

23. Operating mechanism for shifting the eccentric and moving the rollina board drop hammer comprising an armature and connections adapted torelease the roll by gravity movement and electromagnetic meanscomprising a solenoid and magnet operating on the same armature to raiseit and hold it in raised position.

24. A quick-release safety operating mechanism for shifting theeccentric arm of a board drop hammer rolliwhich ccmprisesl jagravity-released pivoted arm connection with theeccentric arm, a springretracted armature connected with the arm and" electromagnetic means forlifting the armature to lift the arm, compress the spring andshift theroll.

25. The methd cf providing for quick release of the roll in. anelectrically operated board drop hammer which consists in shit- 10 ingthe movable .roll against the operation of gravity `and a secondresilient force andreleasing the roll by the combined operation of tHetwo resilient vforces'.

ARTHUR 'ALDRIDGE HOWARD TERHUNE.

